Gr. H. F. Nuttall and Gr. S. Graham-Smith 141 
Piroplasmci muris , Fantham, 1906. 
Through the courtesy of Mr H. B. Fantham we have been able 
to examine one of his films prepared from the blood of a rat infected 
with P. muris. This preparation contained pyriform intracorpuscular 
parasites, singly and in pairs. In the plate accompanying his paper 
corpuscles infected with four and six parasites are shown. The 
secondary mass of loose chromatin has not been observed and no typical 
dividing forms have been found. The latter fact may partially be 
accounted for by the low degree of infection and the lack of material. 
Further the fact that the disease is a chronic one renders the presence 
of many dividing forms at one time improbable. 
Piroplasma equi and P. ovis. 
We have as yet been unable to secure satisfactory specimens of 
these organisms, and none of the papers which have been published 
have contained figures or records of dividing forms such as we have 
described in P. canis. 
Note on Achromaticus vesperuginis, Dionisi 1898. 
This parasite is regarded as a Piroplasma by Sambon 1 , 1908, in 
Manson’s Tropical Diseases (4th edition, p. 841), but we fail to see 
sufficient reason for this assumption. It is true that both Dionisi and 
Gonder figure a few pyriform parasites amongst the many they illustrate, 
and we have found similar forms in films Dionisi gave to one of us in 1899. 
In only one other respect does this organism resemble a typical 
Piroplasvia, namely in the occurrence of four pyriform parasites within 
the corpuscles. Further investigations are required before its position 
can be settled 2 . 
Summary. 
In stained preparations Piroplasma canis, P. bovis and P. pithed 
may be distinguished from other intracorpuscular parasites by the 
presence of intracorpuscular pyriform bodies, usually occurring in pairs 
and less commonly in fours, eights and sixteens. These pyriform bodies 
show a dense mass of chromatin near the pointed end and a loose mass, 
often connected with the dense mass, situated towards the blunt end. 
In suitable preparations peculiar dividing forms, most typically repre¬ 
sented by trilobed forms or more or less pyriform bodies joined to a 
single smaller rounded or elongated mass of protoplasm, may be seen. 
1 We regret to note several inaccurate statements which occur in Sambon’s section 
dealing with the genus Piroplasma. 
2 Gonder (1906, pi. IV) retains the name Achromaticus believing it to be intermediate 
between human malarial parasites and Piroplasma. 
